A FEW REMARKS ON TIN.

Ashburton Guardian, Volume IV, Issue 1065, 4 October 1883, Page 4

A FEW REMARKS ON TIN.

[communicated.]

As some of our townspeople are busying themselves in tin mining at Mount ' Somers, and as we are all in a state of ignorant hopefulness as to the upshot, I thought that a few remarks might be interesting to some of your readers ; more particularly so ss there are but few places where tin is got in payable quantities ... Tin pyrites,'sulphurate of tin, tin sul'phide; commonly massive or in grains. Oolor : Steel gray tc iron black, streak blackish ; brittle H=4; gravity :4 3 46. Composition ; Sulphur, 30; copper, ] S 3 ; iron, 13 ; t’n, 27 —100. Casserteritea —Tin ore ; tin oxide ; in square prisms and octahedrpns, alsof massive and in • Cjgttdns. Color ; Brown, black, with ada- ■" ihantine lustre ; when in crystals, streak pale grey to’ opaque, H=6 - 7 —71; H= f with the blowpipe alone mfua- , on Charcoal with soda yields a glo- I bule of tin. Stream tin is the gravel-like 6th found in debris in low grounds. Thus * ‘you can perceive that the tin ore has the moat weight, and consequently is of the most value ; ft is also easily distin;. uished by its infnsibility, and its yielding tin before the blowpipe on charcoal with soda. Tin ore occurs in granite gneiss and mica date, associated with copper and iron pyrites, topaz, tourmaline, albete, and .talc 1 The principal tin mines now worked are those of Cornwall, Borneo, Malacca, Australia, and Tasmania. Tin occurs in veins or lodes, and sometimes native. From the foregoing the tin ora appears to be able to give the beat results, supposing the quantity to be sufficient, for the following reasons Stream tin-" has become disengaged from sundry of its former envelopments, by their disintegration by atmospheric and other influences. Consequently ft is in a purer state when divested of its iron by oxidation, than it could possibly be. with-it. Now in mining for tin in the bowels of . the earth many tons of rock vUq4 have to be displaced, lifted cSfriea to a sufficient distance so as not to incommode future operations, and supposing the vain or lodo is gained, you now must bear in mind that it would not be fit for the, market in that state, on account of theilarge amount of impurities, that is likely to be combined with-it, as the cost /of carriage by packhorses ormules or wheeled conveyances to a railway and after freight would take all the gilt-off the ginger bread. It would have Msb be brought to the bank and placed in -illeapß to oxidize with occasional wettings to facilitate the disintegration and oxidation in order to fit it for travel. All this latter work takes time, and all the time takes money. There! re, I think it advisable to stick to the streaming if .possible.-sStre am tin may be found in valleys or hollows and creeks, and I should: .not ■be surprised if stream tin should .be found more or less all over the face of a s'annifferous hill owing to the oxidating process that may have been going on for many thousands of years, and should circumstances prove favorable to :-o(>minand. a sufficient force of vater with well. applied hose on the face of such ground, a sufficiency of wash dirt might be found that , would remunerate all parties concerned. Of course they would have to be supplied with a suitable quantity "of boies er flumes to wash the dirt after it was gained, so that you may have a presentable sample; and I may add that tin is not aeted on by the acids. As we are all aware of the utility of tin as a lining to our domestic cooking utensils. Tin is used fnr many purposes in science and art. \7ith mercury it silvers omv mirrors; in oalico printing a preparation is used as a mordant,' and again it is used as a means of preparing the purple of Cassius, and by that means’as a test for gold. 1 happened to be engaged in testing some quartz rock-for gold with aDr Gundry in Christchurch over thirty years ago, and my mind has been bent on minerals on every opportunity that I have had since, and it is surprising the amount of Ignorance fta people as to the constituents ‘of our mother earth, for without her there would be neither vegetable or animal kingdom. ‘ Sir, a prospector; should have a knowledge of geology, mineralogy, and crystalography, or be may pass many valuable minerals for the want of that knowledge. He should also be able to use the blowpipe and be. acquainted with the use of the magnets, in order to save time and trouble in bringing samples to town to ascertain their nature. And all these articles he should have carefully packed in a.box in, his;, tent, as there are pretty certain to be some days that would be unsuitable to go out, and then would be hia opportunity to test his findings, and . enlighten his mates accordingly, as without system it would be like working in a - fog, -and as for himself he should be of a cheerful disposition, with a good pair of legs and hot afraid to use them, a lover of nature and of a reflective mind, and delight in getting up early and be able to wash his .own shirt and cook his own dampers and feel truly thankful that the Almighty has taken suck good care of him. A. Spixxakd.